Method for the production of monohydro-perfluoroalkanes, bis(perfluoroalkyl)phosphinates and perfluoroalkylphosphonates

ABSTRACT

The present invention relates to a process for the preparation of monohydroperfluoroalkanes, bis(perfluoroalkyl)phosphinates and perfluoroalkylphosphonates which comprises at least the treatment of at least one perfluoroalkylphosphorane with at least one base in a suitable reaction medium.

The present invention relates to a process for the preparation ofmonohydroperfluoroalkanes, bis(perfluoroalkyl)phosphinates andperfluoroalkylphosphonates which comprises at least the treatment of atleast one perfluoroalkylphosphorane with at least one base in a suitablereaction medium.

Monohydroperfluoroalkanes have been known for some time and have foundbroad application in various areas, inter alia as ozone-friendlyrefrigerants (WO 01/40400, WO 01/23494, WO01/23491, WO99/36485,WO98/08913), as cleaning agents (WO 01/32323), as a constituent ofetchants for the microelectronics area (US 2001/0005637, U.S. Pat. No.6,228,775) in fire extinguishers (WO010/5468, Combust. Flame, 121, No. 3(2000) pages 471–487, CN 1218702), as blowing agents in foams (U.S. Pat.No. 6,225,365, WO 01/18098) and for the preparation of polymericmaterials and potential anaesthetics (Anesth. Analg (N.Y.), 79, No. 2(1994), pages 245–251, T. Hudlicky et al., J. of Fluorine Chem., 59, No.1 (1992), pages 9–14).

Some of these monohydroperfluoroalkanes, such as, for example,pentafluoroethane, are already produced industrially on a tone scale,the production usually being carried out by catalytic hydrofluorinationof chlorinated hydrocarbons (WO01/77048, EP 1052235).

Disadvantageous in teses processes is firstly the risk associated withthe use of hydrogen fluoride at relatively high temperatures.Furthermore, the processes require particular catalysts, which have tobe prepared in advance by comparatively complex processes. A furtherdisadvantage of these processes is that the preparation of thechlorinated hydrocarbons using chlorine is ecologically dubious, and theproduction costs further increased. Finally, the known processes for thepreparation of pentafluoroethane are not readily suitable for thepreparation of longer-chain monohydroperfluoroalkanes, such as, forexample, 1-hydrononafluorobutanes.

Furthermore, some further processes are known in which pentafluoroethaneis prepared using special fluorinating agents, such as, for example,BrF₃ (R. A. Devis, J. Org. Chem. 32 (1967), page 3478), XeF₂(JP2000/119201), SF₄ (G. Siegemund, Liebigs Ann. Chem., 1979, page 1280,E. R. Bissell, J. of Organic Chem., 29, (1964), page 1591), SbF₅ (G. G.Belenkii et al., Izv. Akad. Nauk SSSR, Ser. Khim., 1972, pages 983,Chem. Abstr. 77 (1972) 75296, A. F. Ermolov et al., Zh. Org. Khim., 17(1981), page 2239, J. Org. Chem. USSR (Engl. Translation), 17 (1981),page 1999, U.S. Pat. No. 2,426,172), MoF₆ (L. D. Shustov et al., Zh.Obshch. Khim., 53 (1983), page 103, J. Gen. Chem. USSR (Engl.translation), 53 (1983), page 85) and CoF₃ (U.S. Pat. No. 6,162,955).

However, the above-mentioned processes have not achieved industrialsignificance since both the respective starting compounds and thefluorinating agents themselves are very expensive.

By contrast, only few processes are known for the preparation oflong-chain monohydroperfluoroalkanes.

According to a first process, monohydroperfluoroalkanes are prepared bydecarboxylation of salts of perfluorinated carboxylic acids (J. D.LaZerte et al., J. Am. Chem. Soc., 75 (1953), page 4525; R. N.Haszeldine, J. Chem. Soc. 1953, page 1548) or corresponding esters (E.Bergman, J. Org. Chem., 23, (1958) page 476) by treatment with strongbases, such as, for example, sodium ethoxide.

According to another process, monohydroperfluoroalkanes are prepared bytreatment of perfluorinated ketones having a trifluoromethyl group onthe carbonyl carbon atom with aqueous alkali (L. V. Saloutina et al.,Izv. Akad. Nauk SSSR, Ser. Khim., 1984, No. 5, pages 1114–1116, Chem.Abstr. 101 (1984) 210504x). These processes also have the disadvantageof the use of expensive starting materials and the high temperaturesnecessary.

1-Hydro-n-nonafluorobutane is furthermore prepared by reduction ofperfluorobutyl iodide using various reducing agents, such as, forexample, zinc dust in methanol (T. Hudlicky et al., J. of FluorineChem., 59, No. 1 (1992), pages 9–14), sodium methoxide (J. L. Howell etal., J. of Fluorine Chem., 72, No. 1 (1995), pages 61–68), by hydrogenin the gas phase at high temperatures (EP 6 32 001), and with the aid ofthe thallium complex [TaCp₂(C₂H₄)H] (P. H. Russel et al., Polyhedron 17,No. 7 (1998), pages 1037–1043).

However, these processes likewise have the disadvantage that they startfrom the starting compound perfluorobutyl iodide, which can only beprepared by comparatively expensive production processes.

The object of the present invention was therefore to provide a processwhich enables the simple and inexpensive preparation ofmonohydroperfluoroalkanes in good yields. The monohydroperfluoroalkanesshould preferably be obtained in high purity. A further object was toprepare bis(perfluoroalkyl)phosphinates and perfluoroalkylphosphonates.

This object has been achieved by the process according to the inventionfor the preparation of monohydroperfluoroalkanes of the general formulaC_(n)HF_(2n+1), in which 1≦n≦8, preferably 1≦n≦4,bis(perfluoroalkyl)phosphinates and perfluoroalkylphosphonates whichcomprises at least the treatment of at least oneperfluoroalkylphosphorane with at least one base in a suitable reactionmedium.

In accordance with the invention, the preparation ofmonohydroperfluoroalkanes by the process according to the invention canin each case be carried out using a perfluoroalkylphosphorane ormixtures of two or more perfluoroalkylphosphoranes. Preferably, only oneperfluoroalkylphosphorane is in each case reacted by the processaccording to the invention.

The perfluoroalkylphosphoranes used in the process according to theinvention can be prepared by conventional methods known to the personskilled in the art.

The perfluoroalkylphosphoranes are preferably prepared byelectrochemical fluorination of suitable starting compounds, asdescribed in V. Ya. Semenii et al., Zh. Obshch. Khim., 55, No. 12(1985), pages 2716–2720; N. Ignatiev, J. of Fluorine Chem., 103 (2000),pages 57–61 and WO 00/21969. The corresponding descriptions areincorporated herein by way of reference and are regarded as part of thedisclosure.

In a preferred embodiment of the process according to the invention, useis made of at least one perfluoroalkylphosphorane of the general formulaI(C_(n)F_(2n+1))_(m)PF_(5-m)in which 1≦n≦8, preferably 1≦n≦4, and m in each case denotes 1, 2 or 3.

Particularly preferred perfluoroalkylphosphorane compounds are selectedfrom the group consisting of difluorotris(pentafluoroethyl)phosphorane,difluorotris(n-nonafluorobutyl)phosphorane,difluorotris(n-heptafluoropropyl)-phosphorane andtrifluorobis(n-nonafluorobutyl)phosphorane.

The treatment of the perfluoroalkylphosphorane compound(s) by theprocess according to the invention is preferably in each case carriedout using only one base. It is of course however also possible to usemixtures of two or more bases in the process according to the invention.The respective bases can also be used in the form of correspondingsolvates, preferably in the form of corresponding hydrates, or in theform of conventional adducts known to the person skilled in the art.

In a further preferred embodiment of the process according to theinvention for the preparation of monohydroperfluoroalkanes, use is madeof a base generally (a), preferably an inorganic base (b) or organicbase (c). The inorganic base (b) is preferably selected from the groupconsisting of alkali metal hydroxides and alkaline earth metalhydroxides.

If an alkali metal hydroxide is used as base (b) in the processaccording to the invention, this can preferably be selected from thegroup consisting of lithium hydroxide, lithium hydroxide monohydrate,sodium hydroxide and potassium hydroxide.

If an alkaline earth metal hydroxide is used as base (b) in the processaccording to the invention, this can preferably be selected from thegroup consisting of barium hydroxide, barium hydroxide octahydrate andcalcium hydroxide.

The process according to the invention for the preparation ofmonohydroperfluoroalkanes can likewise preferably be carried out usingan organic base (c) or organometallic compounds. The base (c) canpreferably be selected from the group consisting of alkylammoniumhydroxides, arylammonium hydroxides, alkylarylammonium hydroxides,alkylphosphonium hydroxides, arylphosphonium hydroxides,alkylarylphosphonium hydroxides, alkylamines, arylamines,alkylarylamines, alkylphosphines, arylphosphines andalkylarylphosphines.

Preferred organometallic compounds can be selected from the groupconsisting of metal alkoxides, preferably alkali metal alkoxides, metalaryloxides, metal alkylthiooxides, metal arylthiooxides, alkylmetalcompounds, arylmetal compounds and Grignard reagents.

If one of the above-mentioned classes of bases contains an alkylradical, this can preferably contain from 1 to 4 carbon atoms. If thecorresponding base contains two or more alkyl radicals, these may ineach case be identical or different, identical alkyl radicals beingpreferred.

If one of the above-mentioned classes of bases contains an aryl radical,this can preferably be an unsubstituted or at least monosubstitutedphenyl radical.

If an alkali metal alkoxide is used as base in the process according tothe invention, this can preferably be derived from sodium and canpreferably have from 1 to 3 carbon atoms.

Suitable reaction media for use in the process according to theinvention are conventional reaction media which are known to the personskilled in the art so long as these do not undergo an irreversiblechemical reaction with the respective base or the respectivemonohydroperfluoroalkane obtained.

In a further preferred embodiment of the process according to theinvention, the reaction medium is water, if desired mixed with one ormore organic solvents, where two-phase systems, such as, for example,mixtures of water and hydrocarbon, are also included in accordance withthe invention.

The process according to the invention for the preparation ofmonohydroperfluoroalkanes can likewise preferably be carried out usingone or more organic solvents, where, in the case where at least twosolvents are used, these can, if desired, be in the form of a two-phasesystem.

Suitable organic solvents which are used in the process according to theinvention, in each case alone or in any desired combination with oneanother, if desired also mixed with water, can preferably be selectedfrom the group consisting of alcohols, ethers, acylamides, sulfoxides,sulfones, nitrites and hydrocarbons.

Preferred alcohols are those having from 1 to 4 carbons in the alkylmoiety. Corresponding alcohols can preferably be selected from the groupconsisting of methanol, ethanol, isopropanol and mixtures of at leasttwo of these above-mentioned alcohols.

The amount of the monohydroperfluoroalkane formed from the respectiveperfluoroalkylphosphorane(s) employed and the type of the furtherreaction products can be controlled in a targeted manner in accordancewith the process according to the invention, for example via thetemperature and/or pressure during the reaction or via the molar ratioof perfluoroalkylphosphorane to base.

Through the choice of parameters, it is possible, for example, for one,two or three perfluoroalkyl groups to be cleaved off specifically fromthe respective difluorotrisperfluoroalkylphosphorane employed.

On removal of one perfluoroalkyl group from the respectivedifluorotrisperfluoroalkylphosphorane, the correspondingbis(perfluoroalkyl)phosphinate, inter alia, is also formed in additionto the desired monohydroperfluoroalkane.

On removal of two perfluoroalkyl groups from the respectivedifluorotrisperfluoroalkylphosphorane, the correspondingperfluoroalkylphosphonate, inter alia, is also formed in addition to thedesired monohydroperfluoroalkane.

If all three perfluoroalkyl groups are removed from the respectivedifluorotrisperfluoroalkylphosphorane, the corresponding phosphate,inter alia, is also obtained in addition to the desiredmonohydroperfluoroalkane.

The respective choice of optimum parameters for the desired combinationof the corresponding monohydroperfluoroalkane, the amount thereof andthe respective further reaction products can be determined by the personskilled in the art by means of simple preliminary experiments.

If, for example, it is intended to remove one perfluoroalkyl group fromthe respective difluorotrisperfluoroalkylphosphorane employed, theprocess according to the invention can preferably be carried out at atemperature of from −10° C. to 100° C. and a mole-equivalent ratio ofdifluorotrisperfluoroalkylphosphorane to base of 1:3.

If, for example, it is intended to remove two perfluoroalkyl groups fromthe respective difluorotrisperfluoroalkylphosphorane employed, theprocess according to the invention can preferably be carried out at atemperature of from 50° C. to 150° C. and a mole-equivalent ratio ofdifluorotrisperfluoroalkylphosphorane to base of 1:4.

If, for example, it is intended to remove the three perfluoroalkylgroups from the respective difluorotrisperfluoroalkylphosphoraneemployed, the process according to the invention can preferably becarried out at a temperature of from 100° C. to 250° C. and amole-equivalent ratio of difluorotrisperfluoroalkylphosphorane to baseof 1:5.

The monohydroperfluoroalkanes prepared by the process according to theinvention can, if necessary, be isolated and, if necessary, purified byconventional methods known to the person skilled in the art.

If they are readily volatile compounds, they can be isolated from thereaction mixture by, for example, condensation in one or more coldtraps, which are preferably cooled with liquid nitrogen or dry ice.

Any isolation and purification of further reaction products is likewisecarried out by conventional methods known to the person skilled in theart, such as, for example, by fractional crystallisation or extractionwith suitable solvents.

If the perfluoroalkylphosphorane is reacted with an inorganic base (b),the bis(perfluoroalkyl)phosphinates and perfluoroalkylphosphonates thusformed can be converted directly or after isolation using an acid,preferably using sulfuric acid, into the correspondingbis(perfluoroalkyl)phosphinic acids and perfluoroalkylphosphonic acids.

The bis(perfluoroalkyl)phosphinic acids and perfluoroalkylphosphonicacids obtained in this way can be converted into the salts byneutralisation, preferably using organic bases (c).

Through selection of suitable bases, the partially alkylated andperalkylated ammonium, phosphonium, sulfonium, pyridinium, pyridazinium,pyrimidinium, pyrazinium, imidazolium, pyrazolium, thiazolium, oxazoliumand triazolium salts salts are preferably prepared.

Particular preference is given to the preparation of salts having acation selected from the group consisting of

where R¹ to R⁵ are identical or different, are optionally bondeddirectly to one another via a single or double bond and are each,individually or together, defined as follows:

-   -   H,    -   halogen, where the halogens are not bonded directly to N,    -   an alkyl radical (C₁ to C₈), which may be partially or        completely substituted by further groups, preferably F, Cl,        N(C_(n)F_((2n+1−x))H_(x))₂, O(C_(n)F(_(2n+1−x))H_(x)),        SO₂(C_(n)F_((2n+1−x))H_(x)), C_(n)F_((2n+1−x))H_(x), where 1<n<6        and 0<x≦

These salts can also be obtained if the salt formed after the reactionof the perfluoroalkylphosphorane with an inorganic base (b) is subjectedto salt interchange, directly or after isolation.

The salt interchanges can be carried out with aryl-, alkyl- oralkylarylammonium or -phosphonium salts. Preference is given to the useof hexafluorophosphates, tetrafluoroborates, hexafluoroarsenates,sulfates, fluorides, chlorides or bromides.

The salts obtained in this way can be worked up in a conventional mannerknown to the person skilled in the art.

The process according to the invention for the preparation ofmonohydroperfluoroalkanes enables the simple, inexpensive and reliablepreparation of these compounds in very good yields. In particular, theperfluoroalkylphosphoranes used as starting compounds can be preparedinexpensively in large quantities.

It is furthermore advantageous that the by-products obtained in theprocess according to the invention, such as, for example, thebis(perfluoroalkyl)phosphinates and perfluoroalkylphosphonates, arethemselves valuable raw materials which are suitable, inter alia, forthe preparation of the corresponding bis(perfluoroalkyl)phosphinic acidsand perfluoroalkylphosphonic acids and thus can be utilisedeconomically. Neutralisation using suitable bases enables preparationfrom them of, for example, bis(perfluoroalkyl)phosphinates andperfluoroalkylphosphonates, which are suitable for use as ionic liquids,surfactants or phase-transfer catalysts.

This furthermore has the advantage that the environmental impact in thereaction by the process according to the invention is kept small, whichfurthermore has a positive effect on the production costs of themonohydroperfluoroalkanes prepared by the process according to theinvention.

The respective monohydroperfluoroalkanes are furthermore obtained inhigh purity immediately after their preparation, i.e. without complexpurification steps.

The invention is explained below with reference to examples. Theseexamples serve merely to explain the invention and do not restrict thegeneral inventive idea.

EXAMPLES Example 1

10.40 g (185.4 mmol) of potassium hydroxide are dissolved in 330 cm³ ofwater in a flask, and the resultant solution is cooled at a bathtemperature of −5° C. 25.53 g (59.9 mmol) ofdifluorotris(pentafluoroethyl)phosphorane are subsequently added via adropping funnel over the course of 15 minutes with stirring. Thereaction mixture is subsequently brought to room temperature. Thegaseous pentafluoroethane formed by alkaline hydrolysis of thedifluorotris(pentafluoroethyl)phosphorane is collected in two subsequenttraps, each of which is cooled with liquid nitrogen. 6.67 g of solidpentafluoroethane having a boiling point of −48° C. are obtained in thecooled traps. This value corresponds to that indicated in the literatureby L. Conte et al. in J. Fluor. Chem., 38, (1988), pages 319–326.

The yield of pentafluoroethane is 92.8%, based on a pentafluoroethylgroup removed from the difluorotris(pentafluoroethyl)phosphorane underthese conditions.

The reaction mixture in the flask furthermore contains a solution ofpotassium bis(pentafluoroethyl)phosphinate ((C₂F₅)₂P(O)OK) and potassiumfluoride. In order to isolate the potassiumbis(pentafluoroethyl)phosphinate, firstly the excess potassium hydroxideis neutralised using a few drops of an aqueous hydrogen fluoridesolution, and the water is removed under reduced pressure. The resultantsolid residue is dried under reduced pressure at 120 Pa and a bathtemperature of 100° C. for two hours.

Potassium bis(pentafluoroethyl)phosphinate is extracted from the driedresidue using 150 cm³ of methanol. The methanol is subsequentlydistilled off under reduced pressure at 120 Pa, and the solid residue ofpotassium bis(pentafluoroethyl)phosphinate is dried. The yield is 19.0g, corresponding to 93.2%, based on thedifluorotris(pentafluoroethyl)phosphorane employed.

The pentafluoroethane is characterised by means of ¹H- and ¹⁹F-NMRspectroscopy and the potassium bis(pentafluoroethyl)phosphinate by meansof ¹⁹F- and ³¹P-NMR spectroscopy.

Pentafluoroethane

The ¹H- and ¹⁹F-NMR spectra are recorded on a Bruker WP 80 SYspectrometer at a frequency of 80.1 MHz for ¹H and 75.4 MHz for ¹⁹F anda temperature of −70° C. To this end, use is made of an FEP(fluoroethylene polymer) tube inside a thin-walled 5 mm NMR tube with anacetone-D₆ film as external lock and TMS or CCl₃F, dissolved in theacetone-D₆ film, as external reference.

¹H-NMR spectrum:

(acetone-D₆ film, reference TMS in the film, δ, ppm) 5.80 tq;²J_(H,F)=52.3 Hz; ³J_(H,F)=2.1 Hz

¹⁹F-NMR spectrum:

(acetone-D₆ film, reference CCl₃F in the film, δ, ppm) −86.54 s (CF₃);−138.55 d (CHF₂); ²J_(H,F)=52.5 Hz

The data obtained correspond to the values disclosed in the literatureby M. D. Bartberger et al. in Tetrahedron, 53, No. 29 (1997), pages9857-9880 and N. Ignatiev et al. in Acta Chem. Scand. 53, No. 12 (1999),pages 1110–1116.

Potassium bis(pentafluoroethyl)phosphinate ((C₂F₅)₂P(O)OK)

The ¹⁹F- and ³¹P-NMR spectra are recorded on a Bruker Avance 300spectrometer at a frequency of 282.4 MHz for ¹⁹F and 121.5 MHz for ³¹P.

¹⁹F-NMR spectrum:

(solvent acetone-D₆, internal reference CCl₃F, δ, ppm) −80.38 m (CF₃);−125.12 dm (CF₂); ²J_(P,F)=67.3 Hz

³¹P-NMR spectrum:

(solvent acetone-D₆, reference 85% by weight H₃PO₄ in D₂O, δ, ppm) 0.72quin; ²J_(P,F)=67.2 Hz

Example 2

5.99 g (142.8 mmol) of lithium hydroxide monohydrate are dissolved in150 cm³ of water in a flask, and the resultant solution is cooled at abath temperature of −10° C. 19.30 g (45.3 mmol) ofdifluorotris(pentafluoroethyl)phosphorane are subsequently added via adropping funnel over the course of 15 minutes with stirring. Thereaction mixture is subsequently brought to room temperature. Thegaseous pentafluoroethane formed by hydrolysis of thedifluorotris(pentafluoroethyl)phosphorane is collected in two subsequenttraps, each of which is cooled with liquid nitrogen. 4.95 g ofpentafluoroethane as a solid are obtained in the cooled traps. The yieldof pentafluoroethane is 91.2%, based on the a pentafluoroethyl groupremoved from the difluorotris(pentafluoroethyl)phosphorane under theseconditions.

The reaction mixture in the flask furthermore contains a solution oflithium bis(pentafluoroethyl)phosphinate ((C₂F₅)₂P(O)OLi) and lithiumfluoride. In order to isolate the lithiumbis(pentafluoroethyl)phosphinate, firstly the excess lithium hydroxideis neutralised using a few drops of an aqueous hydrogen fluoridesolution, the precipitate of lithium fluoride is filtered off, and thewater is removed under reduced pressure. The resultant white solid oflithium bis(pentafluoroethyl)phosphinate is dried under reduced pressureat 120 Pa and a bath temperature of 100° C. for two hours. 13.1 g oflithium bis(pentafluoroethyl)phosphinate containing about 2% by weightof lithium fluoride are obtained, corresponding to a yield of 93.7%,based on the difluorotris(pentafluoroethyl)phosphorane employed.

The pentafluoroethane is characterised by means of ¹H- and ¹⁹F-NMRspectroscopy and the lithium bis(pentafluoroethyl)phosphinate by meansof ¹⁹F- and ³¹P-NMR spectroscopy.

The chemical shifts determined for pentafluoroethane correspond to thevalues indicated in Example 1.

Lithium bis(pentafluoroethyl)phosphinate

The ¹⁹F- and ³¹P-NMR spectra are recorded on a Bruker Avance 300spectrometer at a frequency of 282.4 MHz for ¹⁹F and 121.5 MHz for ³¹P.

¹⁹F-NMR spectrum:

(solvent acetone-D₆, internal reference CCl₃F, δ, ppm) −80.32 m (CF₃);−125.08 dm (CF₂); ²J_(P,F)=72.6 Hz

³¹P-NMR spectrum:

(solvent acetone-D₆, reference 85% by weight H₃PO₄ 15% by weight D₂O inacetone-D₆, δ, ppm) 0.27 quin; ²J_(P,F)=72.7 Hz

Example 3

4.1 g (73.1 mmol) of potassium hydroxide are dissolved in 150 cm³ ofwater in a flask, and the resultant solution is cooled at a bathtemperature of 0° C. 16.87 g (23.2 mmol) ofdifluorotris(n-nonafluorobutyl)phosphorane are subsequently added via adropping funnel over the course of 3 minutes with stirring. The reactionmixture is subsequently brought to room temperature, stirred at thistemperature for eight hours and subsequently refluxed for a furthereight hours. The gaseous 1H-nonafluoro-n-butane formed by hydrolysis ofthe difluorotris(n-nonafluorobutyl)phosphorane is collected in asubsequent trap cooled with dry ice. 3.63 g of liquid1H-nonafluoro-n-butane having a boiling point of 14° C. are obtained inthe cooled trap.

The yield of 1H-n-nonafluorobutane is 71.2%, based on ann-nonafluorobutyl group removed from thedifluorotris(n-nonafluorobutyl)phosphorane under these conditions.

The solution remaining in the flask is separated from the viscousresidue likewise remaining in the flask and neutralised usinghydrochloric acid. In order to isolate the potassiumbis(n-nonafluorobutyl)phosphinate, the water is removed under reducedpressure. The resultant solid residue is dried under reduced pressure at120 Pa and a bath temperature of 100° C. for two hours. The driedresidue is subsequently extracted with three portions of 50 cm³ ofmethanol each, the fractions are combined, the is subsequently distilledoff under reduced pressure at 125 Pa, and the solid residue is dried.The yield of potassium bis(n-nonafluorobutyl)phosphinate is 7.88 g,corresponding to 62.9%, based on thedifluorotris(n-nonafluorobutyl)phosphorane employed.

The 1H-n-nonafluorobutane is characterised by means of ¹H- and ¹⁹F-NMRspectroscopy and the potassium bis(n-nonafluorobutyl)phosphinate bymeans of ¹⁹F- and ³¹P-NMR spectroscopy.

1H-Nonafluorobutane

The ¹H- and ¹⁹F-NMR spectra are recorded on a Bruker WP 80 SYspectrometer at a frequency of 80.1 MHz for ¹H and 75.4 MHz for ¹⁹F anda temperature of −60° C. To this end, use is made of an FEP(fluoroethylene polymer) tube inside a thin-walled 5 mm NMR tube with anacetone-D₆ film as external lock and TMS or CCl₃F, dissolved in theacetone-D₆ film, as external reference.

¹H-NMR SPECTRUM:

(acetone-D₆ film, reference TMS in the film, δ, ppm) 6.14 tt;²J_(H,F)=52.0 Hz; ³J_(H,F)=5.0 Hz

¹⁹F-NMR spectrum:

(acetone-D₆ film, CCl₃F in the film, δ, ppm) −81.31 t (CF₃); −127.93 m(CF₂); −131.06 m (CF₂); −137.92 dm (CF₂); ²J_(H,F)=52.0 Hz

The data obtained correspond to the values disclosed in the literaturepublication by T. Hudlicky et al. in J. of Fluorine Chem., 59, No. 1(1992), pages 9–14.

Potassium bis(n-nonafluorobutyl)phosphinate

The ¹⁹F- and ³¹P-NMR spectra are recorded on a Bruker Avance 300spectrometer at a frequency of 282.4 MHz for ¹⁹F and 121.5 MHz for ³¹P.

¹⁹F-NMR spectrum:

(solvent D₂O, reference CF₃COOH in D₂O=76.53 ppm, δ, ppm) −82.69 tt(CF₃); −122.33 m (CF₂); −123.31 dm (CF₂); −127.46 tm (CF₂);²J_(P,F)=79.5 Hz; ⁴J_(F,F)=9.6 Hz; ⁴J_(F,F)=12.0 Hz; J_(F,F)=1.5 Hz;

³¹P-NMR spectrum:

(solvent D₂O, internal reference 85% by weight H₃PO₄, ppm) 4.81 quin;²J_(P,F)=78.9 Hz

Example 4

7.0 g (124.8 mmol) of potassium hydroxide are dissolved in 10 cm³ ofwater in a flask, and the resultant solution is warmed at a bathtemperature of 70–80° C. 12.18 g (16.8 mmol) ofdifluorotris(n-nonafluorobutyl)phosphorane are subsequently added via adropping funnel over the course of 20 minutes with stirring. Thereaction mixture is subsequently warmed at a bath temperature of 150° C.and stirred at this temperature for a further two hours.

The gaseous 1H-n-nonafluorobutane formed by hydrolysis of thedifluorotris(n-nonafluorobutyl)phosphorane is collected in a subsequenttrap cooled with dry ice.

6.12 g of liquid 1H-n-nonafluorobutane are obtained in the cooled trap.The yield of 1H-n-nonafluorobutane is 82.9%, based on the twon-nonafluorobutyl groups removed from thedifluorotris(n-nonafluorobutyl)phosphorane under these conditions.

The residue remaining in the flask is dissolved in 50 cm³ of water, andthe excess potassium hydroxide is neutralised using aqueous hydrogenfluoride solution.

In order to isolate the dipotassium (n-nonafluorobutyl)phosphonate, thewater is removed under reduced pressure. The resultant solid residue isdried under reduced pressure at 120 Pa and a bath temperature of 100° C.for two hours. The dipotassium (n-nonafluorobutyl)phosphonateC₄F₉P(O)(OK)₂ is subsequently extracted from the dried residue using twoportions of 50 cm³ of methanol each, the fractions are combined, and themethanol is distilled off. The solid residue is subsequently dried underreduced pressure at 125 Pa. The yield of dipotassium(n-nonafluorobutyl)-phosphonate is 5.0 g, corresponding to a yield of79.2%, based on the difluorotris(n-nonafluorobutyl)phosphorane employed.

The 1H-n-nonafluorobutane is characterised by means of ¹H- and ¹⁹F-NMRspectroscopy and the dipotassium (n-nonafluorobutyl)phosphonate by meansof ¹⁹F- and ³¹P-NMR spectroscopy.

The chemical shifts determined for 1H-n-nonafluorobutane correspond tothe values indicated in Example 3.

Dipotassium (n-nonafluorobutyl)phosphonate C₄F₉P(O)(OK)₂

The ¹⁹F- and ³¹P-NMR spectra are recorded on a Bruker Avance 300spectrometer at a frequency of 282.4 MHz for ¹⁹F and 121.5 MHz for ³¹P.

¹⁹F-NMR spectrum:

(solvent D₂O, reference CF₃COOH in D₂O=76.53 ppm, δ, ppm) −81.64 tt(CF₃); −121.94 m (CF₂); −122.86 dm (CF₂); −126.66 tm (CF₂); ²J_(P,F)=68.9 Hz; ⁴J_(F,F)=9.6Hz; ⁴J_(F,F)=13.4 Hz; J_(F,F)=3.9 Hz

³¹P-NMR spectrum:

(solvent D₂O, reference 85% by weight H₃PO₄ in D₂O, δ, ppm) 4.00 tt;J_(P,F)=68.8 Hz; ³J_(P,F)=3.4 Hz

Example 5

8.0 g (190.5 mmol) of lithium hydroxide monohydrate are suspended in 15cm³ of water in a flask, and the resultant suspension is warmed at abath temperature of 70–80° C. 21.21 g (29.2 mmol) ofdifluorotris(n-nonafluorobutyl)phosphorane are subsequently added via adropping funnel over the course of 30 minutes with stirring. Thereaction mixture is subsequently warmed to a bath temperature of 150° C.and stirred at this temperature for a further two hours.

The gaseous 1H-n-nonafluorobutane formed by hydrolysis of thedifluoro-tris(n-nonafluorobutyl)phosphorane is collected in a subsequenttrap cooled with dry ice.

7.24 g of liquid 1H-n-nonafluorobutane are obtained in the cooled trap.The yield of 1H-n-nonafluorobutane is 56.3%, based on the twon-nonafluorobutyl groups removed from thedifluorotris(n-nonafluorobutyl)phosphorane under these conditions.

The residue remaining in the flask is dissolved in 50 cm³ of water, theexcess lithium hydroxide is neutralised using aqueous hydrogen fluoridesolution, and the lithium fluoride precipitate formed is filtered off.In order to isolate the dilithium (n-nonafluorobutyl)phosphonateC₄F₉P(O)(OLi)₂, the water is removed under reduced pressure. Theresultant white solid is dried under reduced pressure at 120 Pa and abath temperature of 100° C. for two hours. 8.0 g of dilithiumn-nonafluorobutylphosphonate are obtained, corresponding to a yield of87.8%, based on the difluorotris(n-nonafluorobutyl)phosphorane employed.

The 1H-n-nonafluorobutane is characterised by means of ¹H- and ¹⁹F-NMRspectroscopy and the dilithium (n-nonafluorobutyl)phosphonate by meansof ¹⁹F- and ³¹P-NMR spectroscopy.

The chemical shifts determined for 1H-n-nonafluorobutane correspond tothe values indicated in Example 3.

Dilithium n-nonafluorobutylphosphonate

The ¹⁹F- and ³¹P-NMR spectra are recorded on a Bruker Avance 300spectrometer at a frequency of 282.4 MHz for ¹⁹F and 121.5 MHz for ³¹P.

¹⁹F-NMR spectrum:

(solvent D₂O, reference CF₃COOH in D₂O=76.53 ppm, δ, ppm) −81.85 tt(CF₃); −122.03 m (CF₂); −123.06 dm (CF₂); −126.79 tm (CF₂);²J_(P,F)=70.1 Hz; ⁴J_(F,F)=9.5 Hz; ⁴J_(F,F)=14.2 Hz; J_(F,F)=3.9 Hz

(solvent acetone-D₆, internal reference CCl₃F, δ, ppm) −80.92 m (CF₃);−120.66 m (CF₂); −122.70 dm (CF₂); −125.62 tm (CF₂); ²J_(P,F)=78.6 Hz;⁴J_(F,F)=9.9 Hz; ⁴J_(F,F)=14.5 Hz; J_(F,F)=3.2 Hz

³¹P-NMR spectrum:

(solvent D₂O, reference 85% by weight H₃PO₄ in D₂O, δ, ppm) 3.81 tt;²J_(P,F)=70.1 Hz; ³J_(P,F)=3.3 Hz

(solvent acetone-D₆, reference 85% by weight H₃PO₄— 15% D₂O inacetone-D₆, δ, ppm) −0.28 t; ²J_(P,F)=78.1 Hz

Example 6

10.24 g (182.5 mmol) of potassium hydroxide are dissolved in 10 cm³ ofwater in a flask, and the resultant solution is warmed at a bathtemperature of 65-70° C. 18.70 g (43.9 mmol) ofdifluorotris(pentafluoroethyl)phosphorane are subsequently added via adropping funnel over the course of 60 minutes with stirring. Thereaction mixture is subsequently warmed at a bath temperature of 120° C.and stirred at this temperature for a further hour.

The gaseous pentafluoroethane formed by hydrolysis of thedifluorotris(pentafluoroethyl)phosphorane is collected in a subsequenttrap cooled with liquid nitrogen.

9.99 g of solid pentafluoroethane are obtained in the cooled trap. Theyield of pentafluoroethane is 94.8%, based on the two pentafluoroethylgroups removed from the difluorotris(pentafluoroethyl)phosphorane underthese conditions.

The residue remaining in the flask is dissolved in 40 cm³ of water, andthe excess potassium hydroxide is neutralised using a few drops of anaqueous hydrogen fluoride solution.

In order to isolate the dipotassium pentafluoroethylphosphonate, thewater is removed under reduced pressure. The resultant solid is driedunder reduced pressure at 120 Pa and a bath temperature of 100° C. forone hour. The dipotassium pentafluoroethylphosphonate is subsequentlyextracted from the solid residue using two portions of methanol of 50cm³ each, the fractions are combined, the methanol is distilled off, andthe resultant residue is dried under reduced pressure at 120 Pa.

16.54 g of dipotassium pentafluoroethylphosphonate di(potassiumfluoride) (C₂F₅P(O)(OK)₂).2KF are obtained, corresponding to a yield of96.1%, based on the difluorotris(pentafluoroethyl)phosphorane employed.

The pentafluoroethane is characterised by means of ¹H- and ¹⁹F-NMRspectroscopy and the dipotassium pentafluoroethylphosphonatedi-(potassium fluoride) by means of ¹⁹F- and ³¹P-NMR spectroscopy.

The chemical shifts determined for pentafluoroethane correspond to thevalues indicated in Example 1.

Dipotassium pentafluoroethylphosphonate di(potassium fluoride)

¹⁹F-NMR spectrum:

(solvent D₂O, reference CF₃COOH in D₂O=76.53 ppm, δ, ppm) −81.86 t(CF₃); −125.91 q (CF₂); −122.70 s (2KF); ²J_(P,F)=68.4 Hz; ³J_(F,F)=1.6Hz

³¹P-NMR spectrum:

(solvent D₂O, reference 85% by weight H₃PO₄ in D₂O, δ, ppm) 3.17 t;²J_(P,F)=68.4 Hz

Example 7

8.50 g (151.5 mmol) of potassium hydroxide are dissolved in 8.8 cm³ ofwater in a flask, and the resultant solution is warmed at a bathtemperature of 70–80° C. 15.77 g (37.0 mmol) ofdifluorotris(pentafluoroethyl)phosphorane are subsequently added via adropping funnel over the course of 90 minutes with stirring.

The gaseous pentafluoroethane formed by hydrolysis of thedifluorotris(pentafluoroethyl)phosphorane is collected in a subsequenttrap cooled with liquid nitrogen.

8.30 g of solid pentafluoroethane are obtained in the cooled trap. Theyield of pentafluoroethane is 93.4%, based on the two pentafluoroethylgroups removed from the difluorotris(pentafluoroethyl)phosphorane underthese conditions.

The chemical shifts determined for pentafluoroethane correspond to thevalues indicated in Example 1.

Example 8

6.23 g (111.0 mmol) of potassium hydroxide are dissolved in 12.18 g ofan ethanol/water mixture (1:1 parts by weight) in a flask, and theresultant solution is warmed at a bath temperature of 55–60° C. 11.43 g(26.8 mmol) of difluorotris(pentafluoroethyl)phosphorane aresubsequently added via a dropping funnel over the course of 45 minuteswith stirring, and the reaction mixture is heated at 80° C. for 10minutes.

The gaseous pentafluoroethane formed by hydrolysis of thedifluorotris(pentafluoroethyl)phosphorane is collected in a subsequenttrap cooled with liquid nitrogen.

5.23 g of solid pentafluoroethane are obtained in the cooled trap. Theyield of pentafluoroethane is 81.3%, based on the two pentafluoroethylgroups removed from the difluorotris(pentafluoroethyl)phosphorane underthese conditions.

The chemical shifts determined for pentafluoroethane correspond to thevalues indicated in Example 1.

Example 9

13.46 g (31.6 mmol) of difluorotris(pentafluoroethyl)phosphorane areadded via a dropping funnel over the course of one hour with stirring to96.5 g (131.1 mmol) of a 20% by weight aqueous solution oftetraethylammonium hydroxide at room temperature.

Warming of the reaction mixture is observed during this operation. Thereaction mixture is subsequently heated at 80° C. for 30 minutes. Thegaseous pentafluoroethane formed by hydrolysis of thedifluorotris(pentafluoroethyl)phosphorane is collected in a subsequenttrap cooled with liquid nitrogen.

7.49 g of solid pentafluoroethane are obtained in the cooled trap. Theyield of pentafluoroethane is 98.8%, based on the two pentafluoroethylgroups removed.

The chemical shifts determined for pentafluoroethane correspond to thevalues indicated in Example 1.

The solution remaining in the flask is evaporated on a rotaryevaporator, and the resultant solid is dried under reduced pressure at120 Pa and a temperature of 100° C., 24.67 g of white crystalline[(C₂H₅)₄N]₂[C₂F₅PO₃].2[(C₂H₅)₄N]F.8H₂O

The [(C₂H₅)₄N]₂[C₂F₅PO₃].2 [(C₂H₅)₄N]F.8H₂O is characterised by means of¹H-, ¹⁹F- and ¹⁹F ³¹P-NMR spectroscopy and by elemental analysis:

The ¹⁹F-, ¹H- and ³¹P-NMR spectra are recorded on a Bruker Avance 300spectrometer at a frequency of 282.4 MHz for ¹⁹F and 121.5 MHz for ³¹P.

¹⁹F-NMR spectrum:

(solvent acetonitrile-D₃, reference CCl₃F, δ, ppm) −79.41 dt (CF₃);−126.74 dq (CF₂); −111.74 (2F—); ²J_(P,F)=54.0 Hz; ³J_(P,F)=1.1 Hz;³J_(F,F)=1.0 Hz

¹H-NMR spectrum:

(solvent acetonitrile-D₃, reference TMS, δ, ppm) 1.21 tm (CH₃); 3.28 q(CH₂); ³J_(H,H)=7.3 Hz

Proton exchange takes place between the H₂O molecules and the deuteriumof the solvent;

³¹P-NMR spectrum:

(solvent acetonitrile-D₃, reference 85% by weight H₃PO₄— 15% D₂O inacetonitrile-D₃, δ, ppm) −1.77 t; ²J_(P,F)=54.2 Hz

Elemental analysis:

calculated for C₃₄H₉₆F₅N₄O₁₁P, C, 47.31%; H, 11.21%; N, 6.49% found: C,47.37%; H, 10.80%; N, 6.40%.

Example 10

50.38 g (159.7 mmol) of barium hydroxide octahydrate are suspended in100 cm³ of water in a flask, and the resultant suspension is warmed at abath temperature of 65–70° C. 22.68 g (53.2 mmol) ofdifluorotris(pentafluoroethyl)phosphorane are subsequently added via adropping funnel over the course of 30 minutes with stirring. Thereaction mixture is subsequently warmed to a temperature of 150° C. andstirred at this temperature for two hours.

The gaseous pentafluoroethane formed by hydrolysis of thedifluorotris(pentafluoroethyl)phosphorane is collected in a subsequenttrap cooled with dry ice.

10.00 g of liquid pentafluoroethane are obtained in the cooled trap. Theyield of pentafluoroethane is 78.3%, based on the two pentafluoroethylgroups removed from the difluorotris(pentafluoroethyl)phosphorane underthese conditions.

The residue remaining in the flask is taken up in 50 cm³ of water andneutralised using an aqueous hydrogen fluoride solution. The bariumfluoride precipitate formed is filtered off.

In order to isolate the barium pentafluoroethylphosphonate, the water isremoved under reduced pressure. The resultant white solid is dried underreduced pressure at 120 Pa and a bath temperature of 100° C. for onehour. 10.6 g of barium pentafluorophosphonate ([C₂F₅P(O)O₂]Ba)containing about 2% by weight of barium fluoride are obtained,corresponding to a yield of 59.2%, based on thedifluorotris(pentafluoroethyl)phosphorane employed.

The pentafluoroethane is characterised by means of ¹H- and ¹⁹F-NMRspectroscopy and the barium pentafluorophosphonate by means of ¹⁹F- and³¹P-NMR spectroscopy.

The chemical shifts determined for pentafluoroethane correspond to thevalues indicated in Example 1.

Barium pentafluoroethylphosphonate

The ¹⁹F-, ¹H- and ³¹P-NMR spectra are recorded on a Bruker Avance 300spectrometer at a frequency of 282.4 MHz for ¹⁹F and 121.5 MHz for ³¹P.

¹⁹F-NMR spectrum:

(solvent D₂O, reference CF₃COOH in D₂O=76.53 ppm, δ, ppm) −81.99 td(CF₃); −126.25 dq (CF₂); J_(P,F)=70.5 Hz; J_(F,F)=1.8 Hz; J_(P,F)=0.5 Hz

³¹P-NMR spectrum:

(solvent D₂O, reference 85% by weight H₃PO₄ in D₂O, δ, ppm) 2.88 t;²J_(P,F)=70.3 Hz

Example 11

16.70 g (52.9 mmol) of barium hydroxide octahydrate are suspended in 20cm³ of water in a flask, and the resultant suspension is warmed at abath temperature of 70–80° C. 17.79 g (24.5 mmol) ofdifluorotris(n-nonafluorobutyl)phosphorane are subsequently added withthe aid of a dropping funnel over the course of 30 minutes withstirring. The reaction mixture is subsequently warmed at a bathtemperature of 120° C. and stirred at this temperature for one hour.

The gaseous 1H-n-nonafluorobutane formed by hydrolysis of thedifluorotris(n-nonafluorobutyl)phosphorane is collected in a subsequenttrap cooled with liquid nitrogen.

7.72 g of solid 1H-n-nonafluorobutane are obtained in the cooled trap.The yield of 1H-n-nonafluorobutane is 71.6%, based on the twon-nonafluorobutyl groups removed from thedifluorotris(n-nonafluorobutyl)phosphorane under these conditions.

The residue remaining in the flask is taken up in 50 cm³ of water andneutralised using an aqueous hydrogen fluoride solution. The bariumfluoride precipitate formed is filtered off.

In order to isolate the barium n-nonafluorobutylphosphonate, the wateris removed under reduced pressure. The resultant white solid is driedunder reduced pressure at 120 Pa and a bath temperature of 100° C. forone hour. 7.0 g of barium n-nonafluorobutylphosphonate([n-C₄F₉P(O)O₂]Ba) containing about 2% by weight of barium fluoride areobtained, corresponding to a yield of 64.87%, based on thedifluorotris(pentafluoroethyl)phosphorane employed.

The 1H-n-nonafluorobutane is characterised by means of ¹H- and ¹⁹F-NMRspectroscopy and the barium n-nonafluorobutylphosphonate by means of¹⁹F- and ³¹P-NMR spectroscopy.

The chemical shifts determined for 1H-nonafluorobutane correspond to thevalues indicated in Example 3.

Barium n-nonafluorobutylphosphonate

¹⁹F-NMR spectrum:

(solvent D₂O, reference CF₃COOH in D₂O=76.53 ppm, δ, ppm) −81.77 tt(CF₃); −122.29 m (CF₂); −123.66 dtm (CF₂); −126.76 tm (CF₂);²J_(P,F)=75.8 Hz; ⁴J_(F,F)=9.7 Hz; ⁴J_(F,F)=13.8 Hz; J_(F,F)=3.6 Hz

³¹P-NMR spectrum:

(solvent D₂O, reference 85% by weight H₃PO₄ in D₂O, δ, ppm) 2.22 t;²J_(P,F)=76.1 Hz

Example 12

10.32 g (183.9 mmol) of potassium hydroxide and 20 cm³ of water areintroduced into an autoclave having a capacity of 100 cm³. The autoclaveis cooled to −30° C., and 9.70 g (22.8 mmol) ofdifluorotris(pentafluoroethyl)phosphorane are added. The autoclave issubsequently closed and heated at 200–210° C. for eight hours with theaid of an oil bath. The autoclave is then brought to room temperature,and an outlet of the autoclave is connected to a cold trap cooled withliquid nitrogen. 7.57 g of pure pentafluoroethane are obtained,corresponding to a yield of 92.2%, based on the three pentafluoroethylgroups removed from the difluorotris(pentafluoroethyl)phosphoraneemployed under these conditions.

The chemical shifts determined for the pentafluoroethane correspond tothe values indicated in Example 1.

Example 13

51.0 g of potassium hydroxide and 50 cm³ of water are introduced into anautoclave having a capacity 350 cm³. The autoclave is cooled to −30° C.,and 95.9 g of a mixture of trifluorobis(n-nonafluorobutyl)phosphorane(60 mol %) and difluorotris(n-nonafluorobutyl)phosphorane (40 mol %) areadded. The autoclave is subsequently closed and heated at 200-210° C.for 18 hours with the aid of an oil bath. The autoclave is then broughtto room temperature, and an outlet of the autoclave is connected to acold trap cooled with dry ice.

68.0 g of pure 1H-nonafluoro-n-butane are obtained, corresponding to ayield 95.2%, based on the two n-nonafluorobutyl groups removed from thetrifluorobis(n-nonafluorobutyl)phosphorane anddifluorotris(n-nonafluorobutyl)phosphorane employed under theseconditions.

The 1-H-nonafluoro-n-butane is characterised by means of ¹H- and ¹⁹F-NMRspectroscopy.

The chemical shifts determined for 1H-nonafluoro-n-butane correspond tothe values indicated in Example 3.

Example 14

Bis(pentafluoroethyl)phosphinic acid

4.09 g (12.0 mmol) of potassium bis(pentafluoroethyl)phosphinate areintroduced into a distillation flask with 8.71 g (88.9 mmol) of 100%sulfuric acid H₂SO₄, and the resultant bis(pentafluoroethyl)phosphinicacid is distilled off under reduced pressure (400 Pa) and an oil-bathtemperature 90-120° C. 3.25 g of a transparent and colourless liquid ofbis(pentafluoroethyl)phosphinic acid, (C₂F₅)₂P(O)OH, are obtained,corresponding to a yields of 89.5%.

The values of the chemical shifts found correspond to the valuesdisclosed in the publication by T. Mahmood, Inorganic Chemistry, 25(1986), pages 3128–3131.

Example 15

1.0 g (10.2 mmol) of 100% sulfuric acid H₂SO₄ are added to a stirredsolution of 3.42 g (10.2 mmol) of barium pentafluoroethylphosphonate in50 cm³ of water. A precipitate of barium sulfate is formed, which isseparated off by filtration. The resultant filtrate is evaporatedcompletely under reduced pressure and dried at 125 Pa and an oil-bathtemperature of 100° C. for a further 6 hours. 1.75 g of a highly viscousliquid of pentafluoroethylphosphonic acid C₂F₅P(O)(OH)₂ are obtained,corresponding to a yield of 83.8%.

¹⁹F-NMR spectrum:

(solvent: acetonitrile-D₃, reference CCl₃F, δ, ppm) −81.03 t (CF₃);−126.74 dq (CF₂); J² _(P,F)=89.4 Hz, J³ _(F,F)=1.6 Hz.

¹H-NMR spectrum:

(solvent: acetonitrile-D₃, reference TMS, δ, ppm) 11.26 br.s (OH)

³¹P-NMR spectrum

(solvent: acetonitrile-D₃; reference: 85% by weight H₃PO₄— 15% by weightD₂O in acetonitrile-D₃): —3.40 t, J² _(P,F)=89.6 Hz.

These data correspond to the values disclosed in the literaturepublication by T. Mahmood and J. M. Shreeve, in Inorg. Chem., 25 (1986),pages 3128–3131.

Example 16

A solution of 0.492 g (2.46 mmol) of pentafluoroethylphosphonic acidprepared as described in Example 15 in 10 cm³ of water is neutralisedusing 3.015 g of 20% by weight aqueous tetraethylammonium hydroxide byslow addition at room temperature with stirring. The water is evaporatedoff under reduced pressure, and the resultant residue is dried underreduced pressure of 120 Pa and a bath temperature of 50° C. for 2 hour.1.115 g of a white solid ofbis(tetraethylammonium)pentafluoroethylphosphonate are obtained. Theyield is 99.0%, based on the pentafluoroethylphosphonic acid employed.

Bis(tetraethylammonium)pentafluoroethylphosphonate was characterised bymeans of ¹⁹F, ³¹P and ¹H-NMR spectroscopy:

¹⁹F NMR spectrum, ppm:

(solvent: acetonitrile-D₃; reference: CCl₃F): −79.49 s (CF₃); −122.10 d(CF₂); J² _(P,F)=54.6 Hz.

¹H NMR spectrum, ppm:

(solvent: acetonitrile-D₃; reference: TMS): 1.20 tm (12H, 4CH₃); 3.29 q(8H, 4CH₂); J³ _(H,H)=7.3 Hz.

³¹P NMR spectrum, ppm:

(solvent: acetonitrile-D₃; reference: 85% H₃PO₄): −2.28 t; J²_(P,F)=54.9 Hz.

Example 17

A solution of nonafluoro-n-butylphosphonic acid, prepared as describedin Example 15 from 3.73 g (8.57 mmol) of bariumnonafluoro-n-butylphosphonate and 0.839 g of 100% by weight sulfuricacid in 20 cm³ of water, is neutralised (pH=7) using 20% by weightaqueous tetraethylammonium hydroxide by slow addition at roomtemperature with stirring. The water is evaporated off under reducedpressure, and the resultant residue is dried under reduced pressure of120 Pa and a bath temperature of 60° C. for 2 hour.

4.59 g of solid of bis(tetraethylammonium) nonafluoro-n-butylphosphonateare obtained. The yield is 96.0%, based on the bariumnonafluoro-n-butylphosphonate employed.

Bis(tetraethylammonium) nonafluoro-n-butylphosphonate was characterisedby means of ¹⁹F, ³¹P and ¹H-NMR spectroscopy:

¹⁹F NMR spectrum, ppm:

(solvent: acetonitrile-D₃; reference: CCl₃F): −80.37 tt (CF₃); −119.57 m(CF₂); −119.72 dm (CF₂); −124.80 m (CF₂); J² _(P,F)=55.6 Hz; J³_(F,F)=4.3 Hz; J⁴ _(F,F)=9.5 Hz.

¹H NMR spectrum, ppm:

(solvent: acetonitrile-D₃; reference: TMS): 1.23 tm (12H, 4CH₃); 3.27 q(8H, 4CH₂); J³ _(H,H)=7.4 Hz.

³¹P NMR spectrum, ppm:

(solvent: acetonitrile-D₃; reference: 85% H₃PO₄): −2.06 t; J²_(P,F)=56.5 Hz.

Example 18

1.43 g of the pentafluoroethylphosphonic acid prepared as described inExample 15 are dissolved in 15 cm³ of water and neutralised (pH=7) using10% by weight aqueous potassium hydroxide by slow addition at roomtemperature with stirring. A solution of 2.09 g (11.9 mmol) of1-ethyl-3-methylimidazolium chlorides in 3 cm³ of water is added at roomtemperature to the resultant aqueous solution of dipotassiumpentafluoroethylphosphonate with constant stirring. The water isevaporated off under reduced pressure, and the resultant residue isdried under reduced pressure of 120 Pa and a bath temperature of 60° C.for 1 hour. 10 cm³ Of isopropyl alcohol are subsequently added to theresidue, and a white precipitate is filtered off and washed twice with 5cm³ of isopropyl alcohol. The isopropyl alcohol is evaporated off underreduced pressure, and the resultant residue is dried under reducedpressure of 1.4 Pa and a bath temperature of 80° C. for 1.5 hour.

2.56 g of an oily liquid ofdi(1-ethyl-3-methylimidazolium)pentafluoroethylphosphonate are obtained.The yield is 85.0%, based on the pentafluoroethylphosphonic acidemployed.

Di(1-ethyl-3-methylimidazolium)pentafluoroethylphosphonate ischaracterised by means of ¹⁹F, ³¹P and ¹H-NMR spectroscopy:

¹⁹F NMR spectrum, ppm:

(solvent: acetonitrile-D₃; reference: CCl₃F): −79.68 s (CF₃); −123.22 d(CF₂); J² _(P,F)=57.9 Hz.

¹H NMR spectrum, ppm:

(solvent: acetonitrile-D₃; reference: TMS): 1.38 t (3H, CH₃); 3.94 s(3H, CH₃); 4.29 q (2H, CH₂); 7.70 s (1H); 7.75 s (1H); 10.82 s (1H); J³_(H,H)=7.2 Hz.

³¹P NMR spectrum, ppm:

(solvent: acetonitrile-D₃; reference: 85% H₃PO₄): −1.28 t; J²_(P,F)=57.4 Hz.

Example 19

A solution 2.4 g (12.0 mmol) of pentafluoroethylphosphonic acid preparedas described in Example 15 in 13 cm³ of water is neutralised (pH=7)using 14.86 g of approximately 40% by weight aqueoustetrabutylphosphonium hydroxide by slow addition at room temperaturewith stirring. The water is evaporated off under reduced pressure, andthe resultant residue is dried under reduced pressure of 1.4 Pa and abath temperature of 70° C. for 2 hour.

7.95 g of a highly viscous liquid are obtained, which slowlycrystallises as a white solidbis(tetrabutylphosphonium)pentafluoroethylphosphonate. The yield is92.4%, based on the pentafluoroethylphosphonic acid employed.

The melting point is 76-79° C.

Bis(tetrabutylphosphonium)pentafluoroethylphosphonate, [(C₄H₉)₄P⁺]₂C₂F₅P(O)O₂ ²⁻, is characterised by means of ¹⁹F, ³¹P and ¹H-NMRspectroscopy:

¹⁹F NMR spectrum, ppm:

(solvent: acetonitrile-D₃; reference: CCl₃F): −79.39 s (CF₃); −121.98 d(CF₂) J² _(P,F)=54.2 Hz.

¹H NMR spectrum, ppm:

(solvent: acetonitrile-D₃; reference: TMS): 0.93 t (12H, 4CH₃); 1.45 m(16H, 8CH₂); 2.37 m (8H, 4CH₂); J³ _(H,H)=7.1 Hz.

³¹p NMR spectrum, ppm:

(solvent: acetonitrile-D₃; reference: 85% H₃PO₄): −1.84 t (1P); 32.73 m(2P); J² _(P,F)=54.6 Hz.

1. A process for preparing a monohydroperfluoroalkane,bis(perfluoroalkyl)phosphinate or perfluoroalkylphosphonate comprisingtreating a perfluoroalkylphosphorane with a) an alkaline earth metalhydroxide, b) an organometallic compound, or c) an organic base, andoptionally treating with, an acid in a reaction medium.
 2. A processaccording to claim 1, wherein the perfluoroalkylphosphorane is reactedwith an alkaline earth metal hydroxide in a solvent, the resultantbis(perfluoroalkyl)phosphinates and perfluoroalkylphosphonates inaddition to the monohydroperfluoroalkanes are converted into thecorresponding bis(perfluoroalkyl)phosphinic acids andperfluoroalkylphosphonic acids directly or after isolation by saltinterchange or subsequent treatment with an acid, and salts are obtainedby subsequent neutralisation.
 3. A process according to claim 1, whereinthe perfluoroalkylphosphorane is a compound of formula I(C_(n)F_(2n+1))_(m)PF_(5−m) in which 1≦n≦8, and m in each case denotes1, 2 or
 3. 4. A process according to claim 1, wherein theperfluoroalkylphosphorane is, difluorotris(pentafluoroethyl)phosphorane,difluorotris(n-nonafluorobutyl)phosphoranedifluorotris(n-heptafluoropropyl)phosphorane ortrifluorobis(n-nonafluorobutyl)phosphorane.
 5. A process according toclaim 1, wherein the organic base is selected from alkylammoniumhydroxides, arylammonium hydroxides, alkylarylammonium hydroxides,alkylphosphonium hydroxides, arylphosphonium hydroxides,alkylarylphosphonium hydroxides alkylamines, arylamines,alkylarylamines, alkylphosphines, arylphosphines andalkylarylphosphines.
 6. A process according to claim 1, wherein thealkaline earth metal hydroxide is barium hydroxide, barium hydroxideoctahydrate or calcium hydroxide.
 7. A process according to claim 1,wherein the organometallic compound is selected from metal alkoxides,alkali metal alkoxides, metal aryloxides, metal alkylthiooxides, metalarylthiooxides, alkylmetal compounds, arylmetal compounds and Grignardreagents.
 8. A process according to claim 1, the reaction medium iswater, optionally mixed with one or more organic solvents.
 9. A processaccording to claim 1, wherein the reaction medium is one or more organicsolvents.
 10. A process according to claim 8, wherein the organicsolvent is selected from alcohols, ethers, acylamides, sulfoxides,sulfones, nitriles and hydrocarbons.
 11. A process according to claim10, wherein the alcohol has one to four carbon atoms in an alkyl moiety.12. A perfluoroalkylphosphonate or bis(perfluoroal)kylphosphinateselected from partially alkylated and peralkylated, phosphonium,sulfonium, pyridinium, pyridazinium, pyrimidinium, pyrazinium,imidazolium, pyrazolium, thiazolium, oxazolium and triazolium salts. 13.A perfluoroalkylphosphonate or bis(perfluoroalkyl)phosphinate accordingto claim 12, having a cation selected from

where R¹ to R⁶ are identical or different, are optionally bondeddirectly to one another via a single or double bond and are each,individually or together, defined as follows: H, halogen, where thehalogens are not bonded directly to N, an C₁ to C₈ alkyl radical, whichmay be partially or completely substituted.
 14. An ionic liquidcomprising a perfluoroalkylphosphonate or bis(perfluoroalkyl)phosphinateaccording to claim
 12. 15. A phase-transfer catalyst or surfactantcomprising a perfluoroalkylphosphonate or bis(perfluoroalkyl)phosphinateaccording to claim
 12. 16. A perfluoroalkylphosphonate orbis(perfluoroal)kylphosphinate according to claim 13, where R¹ to R⁶ areidentical or different, are optionally bonded directly to one anothervia a single or double bond and are each, individually or together,defined as follows: H, halogen, where the halogens are not bondeddirectly to N, or an C₁ to C₈ alkyl radical, which may be partially orcompletely substituted by F, Cl, N(C_(n)F_((2n+1−x))H_(x))₂,O(C_(n)F_((2n+1−x))H_(x)), SO₂(C_(n)F_(2n+1−x))H_(x)),C_(n)F_(2n+1−x))H_(x)), where 1<n<6 and 0<x ≦2n+1.
 17. Aperfluoroalkylphosphonate or bis(perfluoroal)kylphosphinate according toclaim 13, having a cation selected from


18. A perfluoroalkylphosphonate or bis(perfluoroal)kylphosphinateaccording to claim 17, where R¹ to R⁵ are identical or different, areoptionally bonded directly to one another via a single or double bondand are each, individually or together, defined as follows: H, halogen,where the halogens are not bonded directly to N, or an C₁ to C₈ alkylradical, which may be partially or completely substituted by F, Cl,N(C_(n)F_((2n+1−x))H_(x))₂, O(C_(n)F_((2n+1−x))H_(x)),SO₂(C_(n)F_(2n+1−x))H_(x)), C_(n)F_(2n+1−x))H_(x)), where 1<n<6 and 0<x≦2n+1.
 19. A process according to claim 4, in which 1≦n≦4.
 20. A processaccording to claim 10 wherein the alcohol is methanol, ethanol,isopropanol or a mixture thereof.
 21. A process according to claim 1,wherein a perfluoroalkylphosphonate is obtained.
 22. A process accordingto claim 1, wherein a bis(perfluoroalkyl)phosphinate is obtained.
 23. Aprocess according to claim 1, wherein a monohydroperfluoroalkane isobtained.